GLib provides the core application building blocks for libraries and applications written in C. It provides the core object system used
in GNOME, the main loop implementation, and a large set of utility functions for strings and common data structures.

GtkSourceView is a portable C library that extends the standard GTK+ framework for multiline text editing with support for configurable
syntax highlighting, unlimited undo/redo, search and replace, a completion framework, printing and other features typical of a source code
editor. (upstream)

WebKitGTK+ is the GNOME platform port of the WebKit rendering engine. Offering WebKit’s full functionality through a set of
GObject-based APIs, it is suitable for projects requiring any kind of web integration, from hybrid HTML/CSS applications to full-fledged
web browsers, like Epiphany and Midori.

Under the Hood

ATK provides the set of accessibility interfaces that are implemented by other toolkits and applications. Using the ATK interfaces,
accessibility tools have full access to view and control running applications.

AT-SPI2 is a D-Bus based accessibility framework. It defines a D-Bus protocol for providing and accessing application accessibility
information. The project includes a library for bridging the D-Bus protocol to the ATK API, allowing Gtk based applications to be made
accessible.

COGL is a low level OpenGL abstraction library developed for (and part of) Clutter. It is used primarily by Clutter to provide a common
rendering API that works transparently across OpenGL >=1.4, OpenGL ES 1.1 and OpenGL ES 2.0.

libsecret is a library for storing and retrieving passwords and other secrets. It communicates with the "Secret Service" using DBus.
gnome-keyring and ksecretservice are both implementations of a Secret Service.

The tracker-indexer is responsible for indexing all content it is given. The indexer is completely modular, this means that there are
modules or 'backends' which are used for indexing specific content types.

Telepathy is a D-Bus framework for unifying real time communication, including instant messaging, voice calls and video calls. It
abstracts differences between protocols to provide a unified interface for applications.

Twitter-GLib is a GObject-based C wrapper library around the (almost-) RESTful web API provided by Twitter. Twitter-GLib provides an
object-oriented API around the webservice methods and data structures, and allows writing clients for Twitter and all the web services
offering a Twitter-compatible API, like Identi.ca.

Avahi is a system which facilitates service discovery on a local network via the mDNS/DNS-SD protocol suite. This enables you to plug
your laptop or computer into a network and instantly be able to view other people who you can chat with, find printers to print to or find
files being shared. Compatible technology is found in Apple MacOS X (branded Bonjour and sometimes Zeroconf).

libnotify is a library that sends desktop notifications to a notification daemon, as defined in the Desktop Notifications spec. These
notifications can be used to inform the user about an event or display some form of information without getting in the user's way.

Ubuntu

A small little library that was created by pulling out some comon code out of indicator-applet. It passes a menu structure across DBus so
that a program can create a menu simply without worrying about how it is displayed on the other side of the bus.

A small little library that was created by pulling out some comon code out of indicator-applet. It passes a menu structure across DBus so
that a program can create a menu simply without worrying about how it is displayed on the other side of the bus.

Zeitgeist is a service which logs the users's activities and events (files opened, websites visites, conversations held with other
people, etc.) and makes relevant information available to other applications. It is able to establish relationships between items based on
similarity and usage patterns.

A library providing high-level API for X Keyboard Extension known as XKB. This library is indended to support XFree86 and other
commercial X servers. It is useful for creating XKB-related software (layout indicators etc).

Other

Bump is a library designed to make asynchronous programming easy by providing high-level data structures for concurrency management,
including multi-threading and main loop callbacks, in GObject/GIO based projects, especially those written in Vala.

LibESMTP is a library to manage posting (or submission of) electronic mail using SMTP to a preconfigured Mail Transport Agent (MTA) such
as Exim. It may be used as part of a Mail User Agent (MUA) or another program that must be able to post electronic mail but where mail
functionality is not the program's primary purpose.